Kapok fiber is a silky, cotton-like fiber from the pods of the Ceiba tree (Ceiba pentandra). Kapok trees grow naturally in the wild making kapok a sustainable resource. The silky kapok fiber, or floss, is lightweight, nonallergic, nontoxic, resistant to rot, and odorless. It has long been used as a plant-based, hypoallergenic alternative to goose down, providing all the benefits of down without the risk of allergies. The optional Naturepedic King Pillowcase is made of 100% organic cotton sateen, machine washable & also made in USA.